A perforating gun system denotes a system for hollow charges, holding devices for the hollow charges, connecting pieces of the holding device, as well as ballistic initiation and transmission mechanisms, e.g. the detonating cord for firing the hollow charges. The purpose of the perforating gun system is the perforation of pipes in boreholes using hollow charges. A perforating gun is to be understood as a holding device to which, amongst other things, the hollow charges are secured. The ballistic initiation and transmission mechanisms, which will not be described in greater detail here, are also installed in the perforating gun.
So-called Through Tubing Gun (TTG) systems exist in which encapsulated charges are connected with small connecting elements. These also remain in the borehole; such systems, however, are much more unstable. They are limited in length (about 12 m) or in towing capacity and are not stiff/rigid. They therefore cannot absorb any pressure load.
According to the state of the art, after the perforation or after the triggering of the hollow charges, the perforating gun is withdrawn from the borehole. This requires time and involves costs.